Number of results to display per page
Search Results
402. Susceptibility to ischemia-induced arrhythmias and the effect of preconditioning in the diabetic rat heart
- Creator:
- Ravingerová, T., Štetka, R., Dezider Pancza, Oľga Uličná, Atila Ziegelhöffer, and Ján Styk
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, experimental diabetes, myocardial ischemia, preconditioning, arrhythmias, rat heart, 14, and 612
- Language:
- English
- Description:
- Diabetic heart is suggested to exhibit either increased or decreased resistance to ischemic injury. Ischemic preconditioning suppresses arrhythmias in the normal heart, whereas relatively little is known about its effects in the diseased myocardium. Our objective was to investigate whether development of diabetes mellitus modifies the susceptibility to ischemia-induced arrhythmias and affects preconditioning in the rat heart. Following 1 and 9 weeks of streptozotocin-induced (45 mg/kg, i.v.) diabetes, the hearts were Langendorff-perfused at constant pressure of 70 mm Hg and subjected to test ischemia induced by 30 min occlusion of the left anterior descending (LAD) coronary artery. Preconditioning consisted of one cycle of 5 min ischemia and 10 min reperfusion, prior to test ischemia. Susceptibility to ischemia-induced arrhythmias was lower in 1-week diabetics: only 42 % of diabetic hearts exhibited ventricular tachycardia (VT) and 16 % had short episodes of ventricular fibrillation (VF) as compared to VT 100 % and VF 70 % (including sustained VF 36 %) in the non-diabetics (P<0.05). Development of the disease was associated with an increased incidence of VT (VT 92 %, not significantly different from non-diabetics) and longer total duration of VT and VF at 9-weeks, as compared to 1-week diabetics. Preconditioning effectively suppressed arrhythmias in the normal hearts (VT 33 %, VF 0 %). However, it did not provide any additional antiarrhythmic protection in the acute diabetes. On the other hand, in the preconditioned 9-weeks diabetic hearts, the incidence of arrhythmias tended to decrease (VT 50 %, transient VF 10 %) and their severity was reduced. Diabetic rat hearts are thus less susceptible to ischemia-induced arrhythmias in the acute phase of the disease. Development of diabetes attenuates increased ischemic tolerance, however, diabetic hearts in the chronic phase can benefit more from ischem preconditioning, due to its persisting influence., T. Ravingerová, R. Štetka, D. Pancza, O. Uličná, A. Ziegelhöffer, J. Styk., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
403. Svět očima zvířat aneb jak ptáci vnímají barvy
- Creator:
- Šulc, Michal and Marcel Honza
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, ptáci, molekulární biologie, fyziologie, zrak, birds, molecular biophysics, physiology, vision, 2, and 59
- Language:
- Czech
- Description:
- Zbarvení hraje v životě zvířat zásadní roli a je často pod přísným dohledem přírodního a/nebo pohlavního výběru. Abychom mohli objektivně zhodnotit jeho vliv na životní strategie zvířat, je zaprvé důležité barvu správně měřit a zadruhé nahlížet na ni zrakovým aparátem zainteresovaného pozorovatele. Obě tyto metody popisujeme na příkladu ptáků, konkrétně hodnocení mimeze parazitických vajec., Colouration plays a very important role in the life of animals and its evolution is often under natural and/or sexual selection. For objective assessment of the influence of colouration on animal life strategies the colour should be measured properly and evaluated from the perspective of the studied species. These methods are briefly described based on the example of birds, specifically on the mimicry of parasitic eggs., and Michal Šulc, Marcel Honza.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
404. Systems analysis in hypertension: complementary role of physiologists and geneticists
- Creator:
- Josef Zicha, Ivana Vaněčková, and Jaroslav Kuneš
- Format:
- print, bez média, and svazek
- Type:
- article, úvodníky, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hypertenze, fyziologie, genetika, hypertension, physiology, genetics, 14, and 612
- Language:
- English
- Description:
- J. Zicha, I. Vaněčková, J. Kuneš. and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
405. Targeted deletion of MMP-9 attenuates myocardial contractile dysfunction in heart failure
- Creator:
- Moshal, K. S., Rodriguez, W. E., Sen, U., and Tyagi, Suresh C.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, biofyzika, srdeční selhání, physiology, biophysics, heart failure, endothelial-myocyte uncoupling, ventricular contraction, volume overload, left ventricle (LV) rings, aortocaval shunt, 14, and 612
- Language:
- English
- Description:
- Chronic volume overload (VO) on the left ventricle (LV) augments redox stress and activates matrix metalloproteinase (MMP) which causes the endocardial endothelial-myocyte (EM) disconnection leading to myocardial contractile dysfunction. VO-induced MMP-9 activation impairs cardiac functions, in part by endothelial endocardial apoptosis, but the role of MMP-9 on EM functions remains obscure. We conjecture that chronic VO activates MMP-9 and causes EM uncoupling. Arteriovenous fistula (AVF) was created in genetically identical wild type (WT) mice (FVB/NJ) and MMP-9 knockout mice (MMP-9KO, FVB.Cg-MMP9tm1Tvu/J). Sham-operated mice were used as controls. Before experimentation the phenotype analysis of MMP-9KO mice was carried out. In-gel-gelatin zymography for MMP-9 activation was performed on LV homogenates. The EM functions were determined on LV rings using tissue myobath. We report a decrease in MMP-9 activity in left ventricular myocardial extracts in MMP-9 deficient mice after AVF. The responses to drugs affecting cardiac functions (acetylcholine (Ach), nitroprusside and bradykinin) were attenuated in AVF mice suggesting the impairment of EM coupling. Interestingly, the EM functions were restored in the MMP-9 deficient mice after AVF. We suggest a direct cause-and-effect relationship between MMP-9 activation and EM uncoupling in LV myocardium after chronic VO and the possible involvement of MMP-9 in myocardial contractile performance., K. S. Moshal, W. E. Rodriguez, U. Sen, S. C. Tyagi., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
406. Terguride attenuates prolactin levels and ameliorates insulin sensitivity and insulin binding in obese spontaneously hypertensive rats
- Creator:
- Věroslav Golda, Mária Ficková, Ľudmila Pintérová, Jana Jurčovičová, Ladislav Macho, and Zórad, Š.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, prolactin, obese SHR, insulin binding, fat tissue, insulin sensitivity, 14, and 612
- Language:
- English
- Description:
- Glucose tolerance, serum insulin, insulin receptors in epididymal fat tissue, circulating total cholesterol and triglyceride concentrations as well as serum prolactin were studied in obese and lean spontaneously hypertensive rats (SHR) of both sexes. Obese animals displayed insulin resistance and elevated insulin and triglyceride concentrations. Moreover, in obese rats the increased mass of epididymal fat tissue was accompanied with decreased capacity of high affinity binding sites of insulin receptors in the tissue plasma membranes. Terguride treatment lowered prolactin serum levels which was accompanied by ameliorated insulin sensitivity in obese animals of both sexes. In addition, terguride treatment decreased serum insulin and triglyceride concentrations in obese females and at the same time enhanced the affinity of high affinity insulin binding sites. Our results show that obesity in SHR is associated with a decreased capacity of insulin receptors and that prolactin may play a role in obesity-induced insulin resistance, particularly in female rats., V. Golda +, M. Ficková, L. Pinterová, J. Jurčovičová, L. Macho, Š. Zórad., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
407. Testosterone modulates cardiomyocyte Ca2+ handling and contractile function
- Creator:
- Curl, C. L., Delbridge, L. M. D., Canny, B. J., and Wendt, I. R.
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, testosteron, physiology, testosterone, cardiac myocyte, cardiac contractility, gonadectomy, intracellular calcium, isotonic shortening, 14, and 612
- Language:
- English
- Description:
- The extent to which sex differences in cardiac function may be attributed to the direct myocardial influence of testosterone is unclear. In this study the effects of gonadal testosterone withdrawal (GDX) and replacement (GDX+T) in rats, on cardiomyocyte shortening and intracellular Ca2+ handling was investigated (0.5 Hz, 25 oC). At all extracellular [Ca2+] tested (0.5-2.0 mM), the Ca2+ transient amplitude was significantly reduced (by ~ 50 %) in myocytes of GDX rats two weeks post- gonadectomy. The time course of Ca2+ transient decay was significantly prolonged in GDX myocytes (tau, 455±80 ms) compared with intact (279±23 ms) and GDX+T (277±19 ms). Maximum shortening of GDX myocytes was markedly reduced (by more than 60 %) and relaxation significantly delayed (by more than 35 %) compared with intact and GDX+T groups. Thus testosterone replacement completely reversed the cardiomyocyte hypocontractility induced by gonadectomy. These results provide direct evidence for a role of testosterone in regulating functional Ca2+ handling and contractility in the heart., C. L. Curl ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
408. The activity of antioxidant enzymes and the content of uncoupling protein-1 in the brown adipose tissue of hypothyroid rats: comparison with effects of iopanoic acid
- Creator:
- Petrović, N., Gordana Cvijić, and Davidović, V.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, brown adipose tissue, hypothyroidism, rat, antioxidant enzymes, uncoupling protein, 14, and 612
- Language:
- English
- Description:
- The activity of antioxidant enzymes, copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT), as well as that of the mitochondrial FAD-dependent a-glycerophosphate dehydrogenase (a-GPD) in the rat interscapular brown adipose tissue (IBAT) were studied after the treatment with methimazole (MMI) for three weeks or with iopanoic acid (IOP) for five days. Besides, the mitochondrial concentration of uncoupling protein-1 (UCP-1) and the activity of catecholamine degrading enzyme monoamine oxidase (MAO) in the IBAT as well as the activity of the catecholamine synthesizing enzyme, dopamine b-hydroxylase (DBH) in rat serum were examined. Judging by the significantly enhanced level of serum DBH, which is an index of sympathetic activity, and that of IBAT MAO, the increase in MnSOD and CAT activities in the IBAT of hypothyroid (MMI-treated) rats seems to be due to elevated activity of sympathetic nervous system (SNS). However, CuZnSOD activity is not affected by SNS. On the contrary, IOP, which is a potent inhibitor of T4 deiodination into T3 producing "local" hypothyroidism, did not change either SNS activity or activities of IBAT antioxidant enzyme. However, both treatments significantly decreased IBAT UCP-1 content and a-GPD activity suggesting that the optimal T3 concentration in the IBAT is necessary for maintaining basal levels of these key mitochondrial parameters., N. Petrović, G. Cvijić V. Davidović., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
409. The association between oxidative stress and obstructive lung impairment in patients with COPD
- Creator:
- Kluchová, Z., Darina Petrášová, Pavol Joppa, Zlatica Dorková, and Ružena Tkáčová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, nemoci plic, oxidační stres, human physiology, pulmonary diseases, oxidative stress, glutathione peroxidase, lipid peroxidation products, malondialdehyde, 14, and 612
- Language:
- English
- Description:
- An oxidant/antioxidant imbalance is thought to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). We hypothesized that antioxidant capacity reflected by erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities, and serum levels of the lipid peroxidation product malondialdehyde (MDA), may be related to the severity of obstructive lung impairment in patients with COPD. Erythrocyte GPx, SOD and CAT activities, and serum levels of MDA were measured in 79 consecutive patients with stable COPD. Pulmonary functional tests were assessed by bodyplethysmography. Moderate COPD (FEV1 50-80 %) was present in 23, and severe COPD (FEV1 < 50 %) in 56 patients. Erythrocyte GPx activity was significantly lower, and serum MDA levels were significantly higher in patients with severe COPD compared to patients with moderate COPD (GPx: 43.1±1.5 vs. 47.7±2.9 U/gHb, p<0.05, MDA: 2.4±0.1 vs. 2.1±0.1 nmol/ml, p<0.05). Linear regression analysis revealed a significant direct relationship between FEV1 and erythrocyte GPx activity (r = 0.234, p<0.05), and a significant inverse relationship between FEV1 and serum MDA levels (r = -0.239, p<0.05). However, no differences were observed in the erythrocyte SOD and CAT activities between the two groups of patients with different severity of COPD. Findings of the present study suggest that antioxidant capacity reflected by erythrocyte GPx activity and serum levels of the lipid peroxidation product MDA are linked to the severity of COPD., Z. Kluchová, D. Petrášová, P. Joppa, Z. Dorková, R. Tkáčová., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
410. The association study of DRD2, ACE and AGT gene polymorphisms and metamphetamine dependence
- Creator:
- Omar Šerý, Vojtová, V., and Petr Zvolský
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, taqI A polymorphism, angiotensinogen, metamphetamine dependence, 14, and 612
- Language:
- English
- Description:
- We investigated the association between metamphetamine dependence and TaqI A polymorphism of the dopamine receptor D2 gene (DRD2), I/D polymorphism in angiotensin-converting enzyme (ACE) and M235T polymorphism of the angiotensinogen gene (AGT) in 93 unrelated metamphetamine-dependent subjects and 131 controls. Our results did not prove any association of TaqI A polymorphism of the DRD2 gene, I/D polymorphism of ACE gene, and M235T polymorphism of AGT gene with the metamphetamine dependence in Caucasians of Czech origin. However, a significant difference in allele I frequency between male and female control groups for the I/D ACE polymorphism (p<0.03) was found., O. Šerý, V. Vojtová, P. Zvolský., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public